Luton terror plotters discussed sending a toy car carrying a bomb under the gates of a Territorial Army centre, based upon instructions in an al Qaida manual entitled "make a bomb in the kitchen of your mom, Woolwich Crown Court has been told.

Zahid Iqbal, 31, and Mohammed Sharfaraz Ahmed, 25, spoke about making an improvised explosive device (IED) in covert recordings played to the court.

Umar Arshad, 24, and Syed Farhan Hussain, 21, all from Luton, were observed "training for terrorist purposes" on Snowdon "as bears the most resemblance to the mountainous regions of Pakistan", said Max Hill QC, prosecuting.

Iqbal is recorded telling Ahmed: "I was looking and drove past like the TA centre, Marsh Road. At the bottom of their gate there's quite a big gap.

"If you had a little toy car it drives underneath one of their vehicles or something."

Iqbal had suggested sending a toy car underneath the gates of the Luton centre

Iqbal, Ahmed, Umar Arshad, 24, and Syed Farhan Hussain, 21, all from Luton, admitted one count of engaging in conduct in preparation for acts of terrorism between January 1 2011 and April 25 2012 at a hearing on March 1.

Iqbal, of Bishopscote Road, Arshad, of Crawley Road, Hussain, of Cornel Close, and Ahmed, of Maidenhall Road, considered methods materials and targets for attacks.

Opening the prosecution against the men, Max Hill QC, said: "The defendants were subjects of an intelligence led joint operation by the Metropolitan Police Counter Terrorism Command (SO15) and the British Security Service (BSS) into the facilitation of individuals from the UK to Pakistan for extremist purposes connected to al Qaida."

Mohammed Sharfaraz Ahmed, who was observed going on trips to mountainous regions in Pakistan

Mr Hill said the evidence showed that Iqbal had been acting as a "facilitator" for people who wanted to travel for "extremist purposes" and he had direct contact with a Pakistani operative who was given the pseudonym "Modern Sleeve".

Ahmed was observed by surveillance on "numerous occasions" attending a gym for training and going on trips to mountainous regions with others, he said.

He said conversations picked up from covert surveillance revealed that he was carrying out the training with a view to being physically fit for "purposes connected with terrorism", Mr Hill said.

"He stated that Snowdon was a particular favourite location to train because within the UK it bears the most resemblance to the mountainous regions of Pakistan," he said.

Hussain had planned with Iqbal to target the MI5

"The surveillance in Snowdon shows on occasions Ahmed and others carrying out regimental walking, press-ups, running in formation and using logs and branches perhaps as mock firearms."

By spring 2011 Iqbal lost contact with "Modern Sleeve" in Pakistan, he said. As a result of this, and also inspired by information from a series of the banned al Qaida online magazine Inspire, Iqbal and Ahmed began to focus on attack planning in the UK, Mr Hill said.

"They discussed making an IED following instructions from an Inspire magazine which they planned to adapt," he said.

"They also identified a target for such an attack, namely a Territorial Army base in their locality, although they discussed targeting multiple sites at one time," he said.

Umar Arshad

In May 2011 Ahmed and Hussain were recorded in which they discussed the possibility of doing an "inside job" on MI5, Mr Hill told the court.

"Hussain referred to having a cousin in the US Air Force who could do a lot of damage. They later discussed the fact that Ahmed wanted to buy a replica firearm," he said.

A search of Iqbal's house found a hard drive containing a number of items including a copy of 44 Ways to Support Jihad, by Anwar Al Awlaki, the court heard.

A copy of Inspire magazine including articles on how to bypass airport security and avoid detection by X-ray scanning equipment, how to transport explosives in printer cartridges and how packages were shipped to Yemen in cargo planes was also found.